C-LAB · Tool · file integrity
HashCheck
SHA-256 · SHA-1 · SHA-512 · MD5
Verify file integrity, without uploading anything.
HashCheck computes a file's cryptographic fingerprints entirely in your browser with the native Web Crypto API. The file never leaves your device, no server, no upload, no telemetry, and it keeps working offline.
Runs 100% in your browser. Open DevTools → Network and watch: zero requests when you hash.
Local-only
The file is read in-memory and never uploaded. No server touches your data.
Four algorithms
SHA-256, SHA-1, SHA-512 and MD5, computed on-device with the Web Crypto API.
Compare and re-verify
Paste an expected hash, or hash a whole folder into a manifest you can re-check later.
Works offline
Static HTML/JS/CSS, no frameworks or CDNs. Auditable and disconnect-proof.
How does it work, and why trust this tool?
Drop a file here
or
The file is processed entirely in your browser. It never leaves your device.
Algorithms
Compare against expected hash
Paste a hash (any algorithm). We will tell you if it matches one of the computed ones.
Web Crypto API · processed on-device